This Feb. 15, 2010, file photo shows a package of K2 , a concoction of dried herbs sprayed with chemicals. Authorities in 13 states thought they were acting to curb a public health threat when they outlawed a form of synthetic marijuana known as K2: a concoction of dried herbs sprayed with chemicals. But even before the laws took effect, many stores that did a brisk business in fake pot had gotten around the laws by making slight changes to K2's chemical formula, creating knockoffs with names such as "K3," "Heaven Scent" and "Syn."